--- a/modbus/modbus.py Wed Nov 13 11:21:04 2019 +0100
+++ b/modbus/modbus.py Thu May 28 10:54:48 2020 +0100
@@ -83,6 +83,7 @@
</xsd:restriction>
</xsd:simpleType>
</xsd:attribute>
+ <xsd:attribute name="Write_on_change" type="xsd:boolean" use="optional" default="false"/>
</xsd:complexType>
</xsd:element>
</xsd:schema>
@@ -115,7 +116,29 @@
datatacc = modbus_function_dict[function][6]
# 'Coil', 'Holding Register', 'Input Discrete' or 'Input Register'
dataname = modbus_function_dict[function][7]
+ # start off with a boolean entry
+ # This is a flag used to allow the user program to control when to
+ # execute the Modbus request.
+ # NOTE: If the Modbus request has a 'current_location' of
+ # %QX1.2.3
+ # then the execution control flag will be
+ # %QX1.2.3.0.0
+ # and all the Modbus registers/coils will be
+ # %QX1.2.3.0
+ # %QX1.2.3.1
+ # %QX1.2.3.2
+ # ..
+ # %QX1.2.3.n
entries = []
+ entries.append({
+ "name": "Exec. request flag",
+ "type": LOCATION_VAR_MEMORY,
+ "size": 1, # BOOL flag
+ "IEC_type": "BOOL", # BOOL flag
+ "var_name": "var_name",
+ "location": "X" + ".".join([str(i) for i in current_location]) + ".0.0",
+ "description": "MB request execution control flag",
+ "children": []})
for offset in range(address, address + count):
entries.append({
"name": dataname + " " + str(offset),
@@ -270,7 +293,7 @@
<xsd:attribute name="Invocation_Rate_in_ms" use="optional" default="100">
<xsd:simpleType>
<xsd:restriction base="xsd:unsignedLong">
- <xsd:minInclusive value="1"/>
+ <xsd:minInclusive value="0"/>
<xsd:maxInclusive value="2147483647"/>
</xsd:restriction>
</xsd:simpleType>
@@ -388,7 +411,7 @@
<xsd:attribute name="Invocation_Rate_in_ms" use="optional" default="100">
<xsd:simpleType>
<xsd:restriction base="xsd:integer">
- <xsd:minInclusive value="1"/>
+ <xsd:minInclusive value="0"/>
<xsd:maxInclusive value="2147483647"/>
</xsd:restriction>
</xsd:simpleType>
@@ -720,12 +743,32 @@
for iecvar in subchild.GetLocations():
# absloute address - start address
relative_addr = iecvar["LOC"][3] - int(GetCTVal(subchild, 3))
- # test if relative address in request specified range
- if relative_addr in xrange(int(GetCTVal(subchild, 2))):
+ # test if the located variable
+ # (a) has relative address in request specified range
+ # AND is NOT
+ # (b) is a control flag added by this modbus plugin
+ # to control its execution at runtime.
+ # Currently, we only add the "Execution Control Flag"
+ # to each client request (one flag per request)
+ # to control when to execute the request (if not executed periodically)
+ # While all Modbus registers/coils are mapped onto a location
+ # with 4 numbers (e.g. %QX0.1.2.55), this control flag is mapped
+ # onto a location with 4 numbers (e.g. %QX0.1.2.0.0), where the last
+ # two numbers are always '0.0', and the first two identify the request.
+ # In the following if, we check for this condition by checking
+ # if their are at least 4 or more number in the location's address.
+ if ( relative_addr in xrange(int(GetCTVal(subchild, 2))) # condition (a) explained above
+ and len(iecvar["LOC"]) < 5): # condition (b) explained above
if str(iecvar["NAME"]) not in loc_vars_list:
loc_vars.append(
"u16 *" + str(iecvar["NAME"]) + " = &client_requests[%d].plcv_buffer[%d];" % (client_requestid, relative_addr))
loc_vars_list.append(str(iecvar["NAME"]))
+ # Now add the located variable in case it is a flag (condition (b) above
+ if len(iecvar["LOC"]) >= 5: # condition (b) explained above
+ if str(iecvar["NAME"]) not in loc_vars_list:
+ loc_vars.append(
+ "u16 *" + str(iecvar["NAME"]) + " = &client_requests[%d].flag_exec_req;" % (client_requestid))
+ loc_vars_list.append(str(iecvar["NAME"]))
client_requestid += 1
tcpclient_node_count += 1
client_nodeid += 1
@@ -745,12 +788,32 @@
for iecvar in subchild.GetLocations():
# absloute address - start address
relative_addr = iecvar["LOC"][3] - int(GetCTVal(subchild, 3))
- # test if relative address in request specified range
- if relative_addr in xrange(int(GetCTVal(subchild, 2))):
+ # test if the located variable
+ # (a) has relative address in request specified range
+ # AND is NOT
+ # (b) is a control flag added by this modbus plugin
+ # to control its execution at runtime.
+ # Currently, we only add the "Execution Control Flag"
+ # to each client request (one flag per request)
+ # to control when to execute the request (if not executed periodically)
+ # While all Modbus registers/coils are mapped onto a location
+ # with 4 numbers (e.g. %QX0.1.2.55), this control flag is mapped
+ # onto a location with 4 numbers (e.g. %QX0.1.2.0.0), where the last
+ # two numbers are always '0.0', and the first two identify the request.
+ # In the following if, we check for this condition by checking
+ # if their are at least 4 or more number in the location's address.
+ if ( relative_addr in xrange(int(GetCTVal(subchild, 2))) # condition (a) explained above
+ and len(iecvar["LOC"]) < 5): # condition (b) explained above
if str(iecvar["NAME"]) not in loc_vars_list:
loc_vars.append(
"u16 *" + str(iecvar["NAME"]) + " = &client_requests[%d].plcv_buffer[%d];" % (client_requestid, relative_addr))
loc_vars_list.append(str(iecvar["NAME"]))
+ # Now add the located variable in case it is a flag (condition (b) above
+ if len(iecvar["LOC"]) >= 5: # condition (b) explained above
+ if str(iecvar["NAME"]) not in loc_vars_list:
+ loc_vars.append(
+ "u16 *" + str(iecvar["NAME"]) + " = &client_requests[%d].flag_exec_req;" % (client_requestid))
+ loc_vars_list.append(str(iecvar["NAME"]))
client_requestid += 1
rtuclient_node_count += 1
client_nodeid += 1